EGTA结合热处理对香蕉果实CBF冷应答途径相关基因表达的影响

Effects of EGTA combined with heat treatment on expression of CBF cold response pathway related genes in banana fruit

【目的】探讨EGTA[乙二醇双(2-氨基乙基醚)四乙酸]结合热处理对香蕉果实CBF冷应答途径相关基因表达的影响,为研究热处理提高香蕉果实抗冷性的机理提供理论参考。【方法】分别采用热处理(HWD)和EGTA结合热处理(EGTA+HWD)两种方法处理香蕉果实,将处理的香蕉果实置于20℃恒温箱中贮藏3.0 h,然后置于7℃恒温箱中冷藏120.0 h,期间定期采集香蕉果皮,利用实时荧光定量PCR(q RT-PCR)检测MaDREB1D、MaDREB2C、MaDREB3和MaCOR413基因在20和7℃下不同取样时间点的表达情况。【结果】HWD处理的香蕉果实MaDREB1D、MaDREB2C、MaDREB3和MaCOR413基因在20℃贮藏0.5 h时表达量迅速升高,之后又迅速降低,7℃冷藏下这4个基因的表达量整体上呈升高趋势。与HWD处理相比,EGTA+HWD处理明显抑制MaDREB1D基因在20℃贮藏0.5 h时的表达,也降低了MaDREB1D基因在7℃冷藏过程中的表达量;EGTA+HWD处理的MaDREB2C、MaDREB3和MaCOR413基因在20℃贮藏和7℃冷藏中的表达量一直维持在较低水平。【结论】EGTA能抑制香蕉果实CBF冷应答途径相关基因的表达,推测钙信号参与香蕉果实CBF冷应答途径。

【Objective】The effects of ethylene glycol-bis-(2-aminoethylether)-N,N,N’,N’-tetraacetic acid(EGTA)combined with heat treatment on gene expression of CBF cold response pathway related genes in banana fruit were explored to provide theoretical reference for studying the mechanism of heat treatment promoting cold resistance of banana fruit.【Method】Banana fruits were treated by heat treatment(HWD)and EGTA combined with heat treatment(EGTA+HWD)respectively.The treated banana fruits were stored at 20℃for 3.0 h in incubator,then stored at 7℃for 120.0 h.Banana peels were collected regularly during the storage period.Analysis of the four genes(MaDREB1D,MaDREB2C,MaDREB3 and MaCOR413)expression patterns at 20 and 7℃in banana fruit were conducted using real-time fluorescence quantitative PCR(qRT-PCR).【Result】The expression of these four genes in banana fruits was enhanced rapidly after HWD treatment at 0.5 h(20℃),and decreased rapidly later.The expression of these four genes was enhanced by HWD treatment at 7℃in varying degrees.Compared with HWD treatment,EGTA+HWD treatment inhibited the expression of MaDREB1D at 20℃0.5 h and reduced the expression of MaDREB1D at 7℃in cold storage.The expression of three genes of MaDREB2C,MaDREB3 and MaCOR413 treated by EGTA+HWD at 20℃and 7℃remained at a low level.【Conclusion】EGTA inhibits the expression of CBF cold response pathway related genes in banana fruit.It is speculated that calcium signaling may be involved in the regulation of CBF cold response pathway in banana fruit.